摘要
对川西海相雷口坡组地层破碎、水平井后期托压严重、井壁失稳突出等问题进行分析发现,现用油基钻井液体系的封堵润滑性不能有效满足施工需求。为提高油基钻井液的封堵润滑性,通过分子结构设计,采用氮掺杂改性与熔盐法相结合的方式,制备出氮杂石墨烯,并通过热稳定性、分散稳定性、XRD、红外光谱、粒径分析等手段表征其热稳定性、分散性、结构、基团和粒径大小。实验结果表明,当氮杂石墨烯在现场油基钻井液中的加量为0.5%时,高温高压滤失量降低率达到76.2%,润滑系数降低50%左右,抗温180℃,石墨烯与油基钻井液的配伍性好,能够很好地提高油基钻井液的润滑性和封堵性。现场应用表明,石墨烯可以显著改善油基钻井液在施工过程中存在的水平井托压、高摩阻、井壁失稳等问题。通过采用氮杂石墨烯封堵润滑油基钻井液技术,为川西海相易坍塌地层井壁失稳及水平井托压等当前实际问题提出了新思路和技术支撑。
The marine facies Leikoupo formation in the west of Sichuan Province is a broken formation,in the later stage of horizontal drilling,it is frequently unable to exert weight on the drill bit,and borehole wall instability is another problem that haunts the drilling engineers.Analyses of these problems show that the oil-based drilling fluids presently in use have plugging capacity and lubricity that are unable to satisfy the needs of operation.To improve the plugging capacity and lubricity of the oil-based drilling fluids,based on molecular structure design,a nitrogen-containing graphene is developed through a combination of nitrogen doping modification and molten salt method.Using experimental methods,such as thermal stability measurement,dispersibility stability measurement,XRD,IR spectrum and particle size analyzer etc.,the thermal stability,dispersibility,structure,functional group and particle sizes of the nitrogen-containing graphene are studied.The nitrogen-containing graphene was tested for its compatibility,plugging capacity,lubricity and high temperature resistance in active oil-based drilling fluids,and its functional mechanisms in oil-based drilling fluids are analyzed.Experimental results show that when the concentration of the nitrogen-containing graphene in an oil-based drilling fluid is 0.5%,the high temperature high pressure filter loss of the drilling fluid can be reduced by 76.2%,and the coefficient of friction reduced by about 50%.The nitrogen-containing graphene works normally at temperatures up to 180℃.In field operation,the use of the nitrogen-containing graphene significantly mitigated downhole problems such as the inability to exert weight on bit,high friction and borehole wall instability etc.The use of nitrogen-containing graphene has provided a new clue and technical support for solving the aforementioned drilling problems.
作者
张鸿鹄
ZHANG Honghu(Drilling Engineering Research Institute of Sinopec Southwest Petroleum Engineering Co.,Ltd.,Deyang,Sichuan 618000)
出处
《钻井液与完井液》
CAS
北大核心
2024年第3期279-287,共9页
Drilling Fluid & Completion Fluid
基金
中国石油化工股份有限公司科研项目“超深长水平井高温强封堵油基钻井液关键技术”(P22116)
中石化石油工程公司项目“深层特深层油气工程关键技术研究与应用”(XUBG210035)。
关键词
氮杂石墨烯
油基钻井液
封堵润滑性
井壁稳定性
Nitrogen-containing graphene
Oil-based drilling fluid
Plugging capacity and lubricity
Borehole wall stability
